Apparatus for sensing dew and frost

摘要

An apparatus for sensing dew and frost, comprising a sensing portion which includes a substrate (1) having less permittivity than ice and includes a pair of electrodes (2, 3) arranged to touch the substrate (1) and further includes a resistive film (4) on the substrate (1) covering the pair of electrodes (2, 3), the impedance between the pair of electrodes (2, 3) changing in three states, or dry, bedewed and frosted states.